Improvement in saws



T. P. MARSHALL.

Improvement in Saws. No 126 407 Patented May 1872.

J, @da/m4.; a

UNITED STATES PATENT OFFICE.

THOMAS P: MARSHALL, OF TRENTON, NEW JERSEY.

IM PROVEMENT IN SAWS.

Specification forming part of Letters Patent No. 126,407, dated May 7,1872; antedated April 19, 1872.

SPECIFICATION.

I, THoMAs P. MARSHALL, of Trenton, Mercer county, State of New Jersey,have invented certain Improvements in Saws with Detachable Teeth, ofwhich. the following is a specification N atnre and Object of theInvention.

My invention consists of a key adapted to a recess in the blade of asaw, and to a recess in a detachable tooth, substantially as describedhereafter, so that the said key may serve to securely lock the toothafter the latter has been inserted in its place. My invention furtherconsists in the combination, with the said key, of a spring-catch, soadapted to a shoulder in the blade that it will retain the key in theposition to which it has been moved in locking the tooth.

Description of the Accompanying Drawing.

Figure 1 is a view of part of the saw-blade with the tooth and keydetached from the same 5 Fig. 2, a view, showing the key in a recess ofthe blade; and Fig. 3 illustrates the tooth and key fitted to theirplaces.

General Description.

' A represents part of the blade of a circular saw; B, the detachabletooth; and D, the key for securing the tooth. In the blade are a numberof recesses for receiving a corresponding number of teeth, a being oneof these recesses, the opposite edges b and b' of which are shaped tofit similarly-formed grooves in the opposite edges d. and d of thetooth. At the front corner of the recess a the latter conr municateswith a narrow inclined recess, e, on the opposite edges ot which areformed V- shaped ribs, adapted to similarly shaped grooves in the edgesof the key D, to which is dovetailed or otherwise secured a springcatch,f. The V-shaped rib his discontinued at x, so that a shoulder may beformed there, for a purpose rendered apparent hereafter. An inclinedrecess, is formed in the front lower corner of the tooth B, and thisrecess coincides with the inclined recess of the blade when the tooth istted to its place, as shown in Fig. 3. Before the base of the tooth isdriven into the recess ot' the blade, the key D is forced to the end ot'the inclined recess e, as shown in Fig. 2, in doing which the point ofthe spring f must be so pressed toward the key that it will pass theshoulder .r above referred to. The tooth is then fitted into the recessa, after which the key is forced upward by a suitable instrument until aportion of it enters the recess t' and the point of the spring f passesthe shoulder x, when the tooth will be securely locked to the blade andthe key will be retained in its place.

The mode of removing the tooth from the blade will be readily understoodWithout description.

Although I prefer in most cases to arrange the key d at the corner ofthe recess in the blade, it is not absolutely necessary that it shouldoccupy this position, as it may be differently arranged and still serveas an effective medium for locking the tooth; nor is it essential thatthe key and the recess in which it tits should be straight, for it maybe curved, as shown by dotted lines in Fig. 3.

Claims.

1. The detachable tooth B, having a recess, t', coinciding with arecess, e, in the saw-blade, in combination with a sliding key, D,sliding in said recess, and when the tooth is secured t0 the bladeoccupying a position partly in the blade and partly in the tooth, asspecified. 2. In combination with the said sliding key, I claim aspring-catch, j', adapted to a shoulder, a', in a recess, c, ot' theblade, as set forth. In testimony whereof I have signed my name to thisspecification in the presence of two subscribing witnesses.

THOMAS P. MARSHALL. Witnesses:

E. H. BAILY, Wn. A. STEEL.

